Solar activity influence on the ozone vertical distribution from SBUV data

Ozone content in the terrestrial atmosphere is dependent on chemical and dynamical factors including catalytic destruction under the influence of chlorine and bromine, Brewer–Dobson circulation, and large-scale atmospheric waves. The appearance of ozone molecules in the stratosphere is caused by solar ultraviolet radiation as well. Therefore solar activity variations can influence ozone content. The 11-year solar cycle had been earlier identified in the upper stratosphere. Satellite ozone observations were begun from the 1970s are almost continuous from 1979 including the vertical ozone distribution, in particular with the use of Solar Backscattered UltraViolet (SBUV) instruments. These data cover the troposphere and stratosphere layers, from the surface to near 50 km. Vertical ozone distribution over the Ukrainian Antarctic station Akademik Vernadsky (65.25°S, 64.27°W) and in the corresponding latitudinal range 60–65°S is studied in this work with the following analysis of possible solar activity display in other latitudinal belts. Sunspot numbers have been considered as the simplest characteristics of solar activity. We have considered SBUV yearly data paying main attention to the time range from 1979 when the measurements are most reliable. Periodicity in the series of ozone layer content has been studied with use of wavelet transform. Processing of the SBUV data over Vernadsky has shown a dominating period near 10–11 years at the heights 18–31 km. In the troposphere and lower stratosphere, this period is unclear. A similar situation is observed above 31 km indicating the upper altitudinal threshold in the presence of the 10–11-year periodicity in the ozone data. The solar cycle influence on the ozone vertical distribution in the Antarctic region has been studied. From our analysis, the solar cycle plays an important role in the decadal variability of the mid-stratospheric ozone over Vernadsky Station with decrease of the effect both in the troposphere – lower stratosphere and in the upper stratosphere. A similar analysis is also realized for zonal mean ozone at the 60–65°S latitudes belt and for the region of zonal ozone maximum (Casey), where the solar cycle was indicated at the heights 31–37 km. Thus, zonal asymmetry in the heights of the maximum solar cycle effect in the Antarctic ozone exists. Periods close to 11 years are observed in the lower stratosphere of equatorial latitudes exhibiting seasonal dependency. At altitudes, 25–30 km, the southern stratosphere has more evident signs of solar cycle periods than the northern one. The summer upper stratosphere with a high flux of direct solar radiation is also a region with prominent quasi-11 year periods. In sum, three main regions with solar activity influence (tropical lower stratosphere, west Antarctic middle stratosphere, and east Antarctic upper stratosphere) are identified. The asymmetry between solar cycle influence (i) in the northern and southern hemisphere mid-stratosphere and (ii) zonal ozone maximum and minimum over Antarctica is denoted for the first time.

This work was partly supported by the project 19BF051-08 Taras Shevchenko National University of Kyiv and by the International Center of Future Science, Jilin University.